Three films about different aspects of chinas second largest river the yellow river or huang he stone grottoes by the river explores the dozens of gigantic grottoes scattered along the yellow river from dunhuang grotto to longmen grotto and yungang grotto the history of the old ferries looks at the influence of the yellow river ferries on politics the economy local culture and the military the mother river the yellow river explore the three topographies each with over 1000 metres